ES2942365T3 - Procedure to coat a pipe - Google Patents

Abstract

A method and system for evaluating the interior surface and exterior wall conditions of a pipeline while also dynamically installing a repair lining on a pipeline, such as a groundwater pipeline. The system is towed up to the pipeline and backed through it. As the system is withdrawn, one module (12) of the system evaluates the surface condition of the interior of the pipe (6) and another module (14) evaluates the structural condition of the pipe wall. Based on the evaluation data obtained from the two modules (12, 14), an epoxy material is applied to the inner surface of the pipe using a rotary caster (16) that is trailed behind the two modules. Preferably, an epoxy coating (10) is applied to the interior surface of the host pipe in the appropriate thickness based on the condition of the pipe determined by the two modules. (Automatic translation with Google Translate, without legal value)

Description

DESCRIPTION

Procedure to coat a pipe

Background of the invention

The present invention relates generally to a method for evaluating and repairing a stretched pipe by installing a liner inside the pipe. More specifically, the present invention relates to a method in which a device is drawn along a pipe to simultaneously assess the inside surface of the pipe, assess the structural condition of the pipe wall, and apply a curable resin system. to coat the inside of the pipe. A corresponding system is also described.

In all developed parts of the world, there are numerous pipelines that run underground to provide utility services to businesses and residences. These services include water lines, sewer pipes, storm drains, and the like. Since these pipes are installed underground, they are constantly subjected to numerous environmental pressures that cause the pipe to deteriorate. For example, piping can deteriorate due to ordinary aging, the corrosive action of fluids carried in the line, environmental conditions such as exposure to groundwater, or other reasons. Over time, all of the wear factors that impact the pipeline result in holes, cracks, structural breakdown, and other defects in the line that must be repaired to prevent fluid leaks and pipeline collapse issues.

In some cases, the concern is that foreign matter, initially part of the actual pipeline construction, may begin to flake off the interior surfaces of the damaged pipeline and enter the fluid flow within the pipeline. For example, ductile iron pipe has a clay-coated surface that, when it fails, can allow rust to enter the fluid flow. Similarly, asbestos-cement pipes containing asbestos reinforcing fibers can release asbestos into the drinking water contained therein as the pipe wall begins to deteriorate. Finally, there is the possibility of introduction of substances flowing from the surrounding underground environment into the pipeline or for water being transported through the pipeline to flow out through cracks leading to a loss of pressure from the pipeline. water and other problems.

In addition, the pipe wall materials themselves can rupture and deteriorate from the outside as the materials break, corrode, or otherwise wear away the strength of the wall itself. If the walls deteriorate significantly, the pipe is at risk of failure.

The traditional approach to repairing previously identified problems involved excavating the affected pipe and replacing it. Given the millions of miles of pipeline installed in the United States alone, this solution would be prohibitively expensive. In addition, such pipelines are typically located under streets and rights-of-way where excavation would create traffic flow problems and require extensive roadway resurfacing as the replacement procedure is completed. In the event that asbestos-cement pipes need to be repaired, an additional problem must be addressed regarding the need to dispose of large amounts of asbestos waste.

In an attempt to overcome many of these problems associated with traditional excavation procedures, various procedures have been developed to renovate existing underground pipelines. Many of these procedures employ the installation of a liner inside the damaged pipe using a liner hose and a gauge hose. For example, US-4,714,095 (Müller) describes a procedure for recovering an underground sewer pipe with a casing hose and a gauge hose. The coating hose includes an inner layer, which is treated with a first resin, and an outer layer, which is not treated with a resin. The casing hose is placed in the conduit of the pipe. A surface region of a calibration hose, which will come into contact with the inner layer of the coating hose, is coated with a second resin. The calibration hose is then inserted into the coating hose. The resins harden so that the coating hose meets the contact surfaces of the calibration hose.

US-4,770,562 (Müller) describes another procedure for recovering an underground pipe conduit. A coating hose is used which has an inner layer saturated with a resin. The coating hose includes an outer layer, which is perforated to form continuous flow openings for the resin in the inner layer. The casing hose is inserted into the pipe conduit. The casing hose is then shaped to fit the pipe by inserting an auxiliary hose into the casing hose and injecting fluid into the auxiliary hose. The resins harden to form a coating structure on the pipe. After the curing stage, the auxiliary hose can be kept on the casing hose or can be removed using ropes or cables.

US-5,653,555 (Catallo) describes a process for coating a pipe conduit using multiple curing resins. A liner hose, which is coated with a high-strength resin, is placed first inside the canal. The liner hose is then expanded in contact with the inside surface of the conduit by inverting a gauge hose. The calibration hose has a corrosion resistant resin coating. High-strength, corrosion-resistant resin layers are cured by applying a hot fluid. The cured casing hose and the calibration hose form a self-supporting rigid structure. The calibration hose is not removed from the liner.

US-5,680,885 (Catallo) describes a procedure for rehabilitating a damaged pipe using a casing hose and a gauge hose. The inner layer of the coating hose is soaked with an excess volume of resin. The calibration hose contains an absorbent layer of resin. The calibration hose is placed on the casing hose and inverted by applying hot water. After inversion, the resin-absorbent layer of the calibration hose contacts and adheres to the resin-coated layer of the coating hose. After curing, the calibration hose becomes an integral part of the liner.

US-5,706,861 (Wood) describes a process for lining a section of pipe by a "cure-in-place" system using a lining pipe and an inflatable bladder. The casing tube is impregnated with a curable synthetic resin and transported to the pipeline in an inflatable annular bladder. The bladder is inflated and the casing tube is cured to the tubing. The bladder is then peeled from the cured casing pipe and removed from the pipe run by ropes.

US-8,402,911 (Weisenberg) describes a remotely controlled robotic apparatus and method for applying a structural membrane coating to ducts.

Patent application US-5,675,251 (Maclean) describes a device for inspecting the integrity of water distribution pipes, the device being constructed of housing units connected by flexible connectors.

WO 01/76780 (Brown) describes an apparatus for cleaning a pipeline and carrying a payload of instrumentation and sensors using a train of substantially spherical pigs connected by a hinged member.

US-6,820,653 (Hagen) describes a multi-module pipeline inspection and repair device that includes a base module, a camera module, a sensor module, an MFL module, a brush module, a set/patch test module and a marker module.

Although the conventional procedures described above can be somewhat effective in repairing pipelines, they still suffer from various problems. For example, problems arise regarding the inversion of a felt liner because it is relatively delicate and tends to break or fray during the inversion procedure. In addition, it is very difficult to pull prior art casing around corners, resulting in cracked seals at such junctions. In addition, pipe joints found at corners and periodically along the length of the pipe form voids that cannot be completely filled by prior art methods. Therefore, prior art procedures cannot do anything to improve the strength of the pipe at its joints. Another difficulty is that once a casing has been installed, identification of supply pipe laterals is difficult to identify and clear.

Furthermore, none of the above procedures provide a real-time analysis of the state of the pipeline. Although these systems place a coating on the pipe, they do not make a determination regarding the condition of the interior surface or the condition of the structural wall of the pipe. As a result, the lining procedure simply performs a “one size fits all” approach that may not actually address the problems with the pipeline. Additionally, the approach can result in too much or too little material being added to the pipe relative to the condition of the pipe.

In view of the above, there is a need for a method and system for rehabilitating a pipeline that evaluates the condition of the inside surface of the pipeline, as well as the condition of the pipe wall while additionally applying an inside coating for the repair. of the pipe. There is also a need for a method and system that can be pulled along the inside of a pipe that interactively controls the thickness of an applied coating based on a real-time assessment of the condition of the inside surface of the pipe, as well as the pipe wall condition

Brief summary of the invention

In this regard, the present invention provides a method as defined in claim 1 for evaluating the interior surface and exterior wall conditions of a pipeline while also dynamically installing a repair coating on a pipeline, such as a water pipeline. underground. The installation of a lining of this type makes it possible to repair and recover a damaged pipe and place it in conditions of normal use. In addition, the evaluation procedure makes it possible to determine if the pipeline requires the installation of additional reinforcing material, such as a lining. According to the method of the present invention, the inner surface The pipe to be repaired and salvaged is first prepared by removing excess debris and dirt. Preparation is preferably done with the appropriate surface preparation material based on the pipe material and condition.

This description includes a system that is used in the process of the invention. The system is towed into the pipeline and pulled back through the pipeline. As the system is withdrawn, one module in the system evaluates the surface condition of the inside of the pipe and another module evaluates the structural condition of the pipe wall. Based on the evaluation data obtained from the two modules, an epoxy material is applied to the inner surface of the pipe using a centrifugal molding machine that is removed behind the two modules. Preferably, a coating of epoxy is applied to the inner surface of the main pipe to the appropriate thickness using a machine such as a spin-casting machine which coats the walls of the pipe as it travels along the pipe.

This invention works intelligently to reduce the time required to assess and repair a pipeline. Furthermore, the system applies only the amount of material necessary to repair the existing state of the pipeline in real time.

Therefore, an object of the present invention is to provide a new and novel method of coating the inner surface of a pipe to repair and recover the pipe so that it can be used normally in a leak-free condition. Another object of the invention is to provide a structural coating process that effectively seals all cracks and flaws in an existing pipeline. A further object of the invention is to provide a coating procedure that evaluates the condition of the pipeline and uses that data to apply the coating thickness required to effect a repair that is relatively inexpensive to carry out compared to the procedures of the prior art without sacrificing the integrity of the seal and repair achieved by the process of the present invention.

This, along with other objects of the invention, along with various features of novelty that characterize the invention, are pointed out with particularity in the claims appended thereto and forming a part of this description. For a better understanding of the invention, its operational advantages and the specific objects achieved by its uses, reference should be made to the accompanying drawings and descriptive matter in which a preferred embodiment of the invention is illustrated.

Brief description of the drawings

In the drawings illustrating the presently contemplated best mode for carrying out the present invention:

Figure 1 is a representative view of a small diameter piping system in the context of a residential home and

Figure 2 is an illustration showing the piping system that is filled with epoxy resin according to the process of the present invention.

Detailed description of the invention

Now referring to the drawings, the method of repairing a pipeline in accordance with the teachings of the present invention is generally shown and illustrated in the figures. In summary, the system described in this invention is used to simultaneously inspect and repair a damaged underground pipeline, such as a water line, so that it can be used in the normal course without undesirable leaks. As can be understood, cracks and leaks in a fluid line are undesirable for the associated pressure drops and flow inefficiencies. Also, in a cracked pipe, particles are commonly dislodged from the internal surface of the pipe, thus contaminating the fluid flowing through the pipe.

Referring first to Figure 1, a side cross-sectional view of a typical pipe installation is shown. The main pipe or tube 6 is installed in the ground 7 where there are several cracks 8 that represent undesirable leakage. The pipe 6 includes a horizontal section 6a and a vertical section 6b. A common pipe 6, as shown in Figure 1, is typically made of concrete, coated ductile iron, clay tile, or asbestos-cement. Foreign matter, such as dirt, accumulates on the surfaces of the inner wall 9 over time. The residues (not shown) form hard scale deposits on the wall surfaces, and these scales are difficult to remove. Similarly, if pipe 6 is constructed of ductile iron, as the interior coating fails, rust deposits accumulate on the interior surfaces 9 of main pipe 6. Also, degradation of pipe 6 over time it causes parts of the pipe structure 6 itself to break, a procedure which is further aggravated as cracks appear in the pipe.

In addition to a breakdown of the internal surface of the pipe, the walls of the pipe begin to deteriorate. Cracks and external breakdown of the pipe wall lead to further deterioration of the integrity of the pipe.

Normally, in a repair procedure, the inner surface 9 of the pipe 6, to be repaired, is preferably first prepared to remove the aforementioned debris and dirt to ensure a good bond, as will be described in detail below. Preferably, the inner wall surfaces 9 of the pipe 6 are cleaned by injecting highly pressurized water into the pipe. The pressurized water flow hits the inner walls and the walls are scrubbed. For example, water is provided at 30,000 psi (2,068 bar) to ensure a clean surface. Even higher pressure can be used, if necessary. Known water spray devices are used for this process step. The injected water substantially removes foreign debris to leave a remaining clean interior wall 9 surface. Although high pressure water is preferably used, air or steam may be used instead. Furthermore, additional cleaning agents are preferably not used, but such cleaning agents could be added to water, air or steam to aid cleaning depending on the application and environment. After surface cleaning is complete, any remaining standing water should be removed, such as from the bottom of pipe 6. High pressure air, using known air blowing equipment, is injected into the pipe to clear any remaining water and cleaning media.

With the inside surface 9 of the pipeline 6 cleaned and prepared, the apparatus described in this invention is inserted into the pipeline as depicted in Fig. 2. The apparatus is a towed coating and inspection system that is arranged to have at least three spheres in a relationship united and separated. One of the spheres 12 includes scanning equipment therein for reading and mapping the condition of the interior surface of the pipe. Such scanning equipment may include, but is not limited to, cameras and/or laser scanners. Another of the spheres 14 includes scanning equipment for detecting the structural condition of the pipe wall and the thickness of the pipe wall. Preferably, said equipment includes a sonar device. Another of the spheres 16 is formed to house a coating device, such as a rotary spray head system, for applying a coating to the inside surface of the pipe.

It should be noted that the coating device is preferably housed in the last sphere 16 of the coating and inspection system so that none of the coating and inspection system is pulled through the newly applied coating materials. The relative positioning of the other spheres 12 and 14 is not critical since the inner surface scan and the outer pipe wall scan can be performed in any order that makes the relative order of those spheres 12 and 14 unimportant. critical to the present invention.

An umbilical feed line 18 connects all the spheres and serves as a tow line for the coating and inspection system, as well as an electronic communication line with a control computer 20 and a feed line for supplying a coating material to apply through the coating device. In operation, the first and second spheres 12, 14 scan the condition of the pipeline and feed the data to the computer 20 via the umbilical line 20. The computer 20 using the data determines the required coating thickness to be applied to backfill. cracks or holes in the pipe. Once the computer 20 determines the thickness of the coating, it regulates the flow rate and/or speed of the coating device to increase or decrease the coating flow to correctly replace the lost structural value of the pipe.

The arrangement of separate spheres connected by a flexible umbilical allows the system to be pulled through pipelines that include bends rather than requiring repairs to be made only on straight runs. This arrangement introduces flexibility, allowing the device to be pulled around tight bends in pipes without getting caught or compromised in corners.

The coating device applies a quick-setting resin 10 which is sprayed onto the inner wall surfaces 9 according to this invention. The resin 10 is sprayed onto the wall surfaces 9 using the well-known epoxy “ spinning ” technology where the coating device is contained in the last sphere 16 passing through the pipe section 6 to be coated. . The details of such an applicator need not be discussed in detail herein as such apparatus are well known in the art.

Based on the data collected on the condition of the pipeline, it can be determined if further remediation of the pipeline is needed beyond the application of a coating. In such a case, an engineer can review the data and determine if additional reinforcement in the form of a coating application is needed.

Many different types of curable resins can be used to coat the inner walls 9 of the pipe 6 and the inner layer of the liner if necessary. Preferably, the quick-setting resin is a moisture-curing type and contains a light-colored pigment agent. The thermosetting resin should have good adhesive strength and have high strength (eg, high flexural modulus, flexural strength, tensile modulus, and tensile strength properties). Slow curing resins can be used. For example, polyester; vinyl esters such as urethane-based vinyl esters, and bisphenol A-fumarate-based vinyl esters and epoxy resins may be used. Epoxy resins are particularly preferred. For example, the assignee of the present invention employs an epoxy product under product number S301 for resin 10 and a product epoxy under product number T301 for resin 17. Quick-setting resin 10 is applied to the inner walls of pipe 9 and thermosetting resin 17 to the felt inner layer 16 of casing hose 12 in a non-liquid form. cured.

Thus, it can be seen that the present invention provides a method for evaluating the interior surface and exterior wall conditions of a pipeline while also dynamically installing a repair lining in a pipeline, such as a groundwater pipeline. The method employs a system that further provides for an intelligent coating application such as an epoxy coating that is applied to the inner surface of the main pipe at the appropriate thickness based on the condition of the pipe determined by the two modules. For these reasons, the present invention is believed to represent a significant advance in the art, having substantial commercial merit.

Although a certain specific structure embodying the invention is shown and described herein, it will be apparent to those skilled in the art that various modifications and rearrangements of parts can be made without departing from the scope of the underlying inventive concept and that the same is not limited to the particular shapes shown and described herein, except to the extent indicated by the scope of the appended claims.

Claims (5)

Yo. A procedure for inspecting and coating the interior surface walls of a piping system (6), the procedure comprising: transporting a plurality of housings (12, 14, 16) through said piping system using an umbilical attachment (18), wherein the umbilical attachment connects said housing to another; evaluating a condition of the interior surface walls of said piping system using a first scanning equipment contained in the first of said housings; evaluating the structural condition of the wall of said piping system using said second scanning equipment contained in the second of said housings; and applying a coating material (10) to said interior surface of said piping system from a coating device contained in the third of said housings; wherein a control computer (20) is connected to said umbilical attachment, receiving said control computer and recording data on the status of said piping system from said first and second scanning equipment, and wherein the control computer controls a rate of application of said coating device as a function of the condition of said piping system; wherein the coating material is supplied to the coating device from the umbilical attachment and said umbilical attachment is used to transmit data between the control computer and the housings. The method of claim 1, wherein said housings (12, 14, 16) are spherical. The method of claim 1, wherein said scanning equipment is selected from the group consisting of: cameras, laser scanners, and sonar. The method of claim 1, wherein said coating device is a rotary spray head. The method of claim 1, wherein said housings (12, 14, 16) are in spaced relationship and connected through said umbilical attachment (18) allowing said apparatus to be flexible.